Vibration monitoring system and method

ABSTRACT

A method detects the presence of a vehicle on a railway track using a sensing processor monitoring a sensing system for detecting vibration into ground installed along the railway track. The sensing system includes a detection module for detecting a vehicle on the railway track. The method includes an initialization step which includes the sub-steps of emitting a first signal to be received by the sensing processor through the sensing system, sending a first message to the sensing processor, monitoring the sensing system, and configuring the detection module in function of the received first signal and configuration data received in the first message. The configuration data can include location of the initialization device, intensity/magnitude of the first signal, emission time of the first signal, and/or type of object corresponding to the first signal.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. patent applicationSer. No. 14/501,177, filed on Sep. 30, 2014, which is herebyincorporated by reference herein in its entirety.

FIELD OF THE INVENTION

Embodiments of the subject matter disclosed herein relate to monitoringsystems and methods.

BACKGROUND OF THE INVENTION

Some known systems sense vibrations propagating through the ground inorder to detect the presence of one or more objects. These systems canexamine the vibrations that are sensed in order to attempt to identifythe objects, determine where the objects are located, and the like. Oneexample of such systems senses ground vibrations using a fiber opticcable extending beneath or near rail tracks. While these fiber opticcables may have been placed along the rail track to provide networkconnectivity, some rail companies have the ability to use these fiberoptic cables to monitor vibrations in the ground. These vibrations canbe used to attempt to identify the passage of rail vehicles along thetrack.

One problem with these known systems is that the systems are not “vital”systems. For example, the systems may be unable to automatically correctchanges in sensed vibrations that are caused by external factors.Changes in the weather and other factors may change the vibrationsand/or the propagation of vibrations through the ground, and can hinderor block the ability of these systems to accurately identify railvehicles based on the vibrations that are generated. These systems maysuffer from incorrectly detecting a rail vehicle based on vibrationsthat are not caused by the rail vehicle, but that appear to be caused bya rail vehicle due to the impact of environmental conditions on thepropagation of the vibrations. Similarly, these systems may suffer fromfailing to detect a rail vehicle based on vibrations that are caused bythe rail vehicle, but that do not appear to be caused by a rail vehicledue to the impact of environmental conditions on the propagation of thevibrations.

Additionally, existing systems typically rely on a one-time calibrationof the exact location of the fiber optic cables. Changes in the fiberoptic cable or interrogation equipment subsequent to calibration,therefore, can introduce errors into the data utilized to detectvehicles. For example, if the fiber optic cable characteristics or thefiber optic cable itself is moved, data skewing can occur and theaccuracy of the system can be affected. Accordingly, there is a need fora system and method that is capable of ensuring that the physic fiberoptic cables have not moved, and which can be calibrated to account forany such movements.

Moreover, initial configuration and calibration of the existing systemsis complex, time-consuming, which implies that the installation of suchsystems is very long and requires a lot of time and/or many people onsite to configure the system.

BRIEF DESCRIPTION OF THE INVENTION

In one embodiment, the invention concerns a method for detecting thepresence of a vehicle on a railway track, using a sensing processormonitoring a sensing system for detecting vibration into groundinstalled along the railway track and comprising a detection module fordetecting a vehicle on the railway track. The method comprises aninitialization step comprising the sub-steps of: at an initializationdevice, emitting a first signal to be received by the sensing processorthrough the sensing system; at the initialization device, sending to thesensing processor, a first message comprising configuration data chosenamong, location of the initialization device, intensity/magnitude of thefirst signal, emission time of the first signal, type of objectcorresponding to the first signal; at the sensing processor, monitoringthe sensing system; and at the sensing processor, configuring thedetection module in function of the received first signal and thereceived configuration data.

Preferred embodiments of the invention are the subject matter of thedependent claims, whose content is to be understood as forming anintegral part of the present description.

In another embodiment of the invention, the method (e.g., for sensingvibrations) includes introducing baseline vibrations into a fiber opticcable with one or more of a designated frequency or a designatedamplitude, monitoring changes in the baseline vibrations using the fiberoptic cable, and determining information about environmental conditionsoutside of the fiber optic cable based at least in part on the changesin the baseline vibrations that are monitored.

In another embodiment, the invention concerns a system (e.g., amonitoring system) including a control system and a sensing system. Thecontrol system is configured to introduce baseline vibrations into afiber optic cable with one or more of a designated frequency or adesignated amplitude. The sensing system is configured to monitorchanges in the baseline vibrations using the fiber optic cable and todetermine information about environmental conditions outside of thefiber optic cable based at least in part on the changes in the baselinevibrations that are monitored.

In another embodiment, the invention concerns a sensing system includesone or more sensors and one or more sensing processors. The one or moresensors are configured to examine light traveling through a fiber opticcable extending along and beneath a route traveled by vehicles. The oneor more sensing processors are configured to monitor changes in baselinevibrations introduced into the fiber optic cable at designated times,and to determine information about environmental conditions outside ofthe fiber optic cable based at least in part on the changes in thebaseline vibrations that are monitored.

The invention concerns also a detecting system for detecting thepresence of a vehicle on a railway track having the features defined inclaim 20.

BRIEF DESCRIPTION OF THE DRAWINGS

Reference is made to the accompanying drawings in which particularembodiments and further benefits of the invention are illustrated asdescribed in more detail in the description below, in which:

FIG. 1 is a schematic diagram of a vibration monitoring system, i.e. ofa detecting system for detecting the presence of a vehicle on a railwaytrack according to one embodiment;

FIG. 2 schematically illustrates a sensing system of the detectingsystem shown in FIG. 1 during movement of an object of interestaccording to one embodiment;

FIG. 3 illustrates one example of a frequency spectrum of vibrations ofinterest generated by movement of the object of interest shown in FIG. 2as detected by the sensing system shown in FIG. 1;

FIG. 4 illustrates a frequency spectrum of baseline vibrations generatedby a control system shown in FIG. 1 during different environmentalconditions according to one embodiment;

FIG. 5 illustrates a flowchart of a method for monitoring vibrationsaccording to one embodiment;

FIG. 6 illustrates a flowchart of a method for verifying the integrityof the vibration monitoring system shown in FIG. 1;

FIG. 7 illustrates a flowchart of a method for determining the locationstatus of a calibration device of the vibration monitoring system shownin FIG. 1;

FIG. 8 is a schematic diagram of a vibration monitoring system, i.e. ofa detecting system for detecting the presence of a vehicle on a railwaytrack according to one embodiment;

FIG. 9 illustrates a flowchart of the steps of a method for detectingthe presence of a vehicle on a railway track according to one embodimentof the invention realized by the detecting system of FIG. 8;

FIG. 10 illustrates a flowchart of the sub-steps of an initializationstep of the method of FIG. 9;

FIG. 11 illustrates a flowchart of the sub-steps of a security step ofthe method of FIG. 9; and

FIG. 12 illustrates a flowchart of the sub-steps of a control step ofthe method of FIG. 9;

FIG. 13 illustrates a flowchart of the sub-steps of a detecting step ofthe method of FIG. 9.

DETAILED DESCRIPTION OF THE INVENTION

One or more embodiments of a vibration monitoring system and method aredescribed herein. These systems and methods can generate vibrations thatpropagate through a portion of the ground that includes one or moresensing cables. The sensing cable can be used to detect the vibrations.As one example, a fiber optic cable can be used as the sensing cable,with changes in refraction of light in the fiber optic cable beingrepresentative of the vibrations that propagate through, into, or aroundthe cable. Based on the magnitude (e.g., amplitude), frequency, period,or the like, of the vibrations that are detected, the presence and/orlocation of one or more objects on the ground can be determined. Forexample, passage of a vehicle above the sensing cable can be detected,as well as the speed, direction of travel, size, or the like, of thevehicle. Optionally, changes in the vibrations can be used to identifydamaged segments of a route being traveled upon by the vehicle.

In one aspect, the vibration monitoring systems and methods can detectvibrations caused by moving objects and determine information about thevibrations and/or objects based on the detected vibrations. Thisinformation that is determined can include peaks, waveforms,frequencies, amplitudes, or the like, in a frequency spectrum of thevibrations, or other information. This information can be used toidentify the moving object, determine a location of the moving object,determine a speed of the object, identify a portion of a route beingtraveled on by the object that may be damaged, or the like.

The vibrations may change due to factors other than the moving objects(e.g., moving vehicles, damaged routes, or the like). For example, indifferent environmental conditions (e.g., different times, seasons,periods of condensation, etc.), the same object may cause the vibrationmonitoring systems and methods to detect different vibrations. Thedifferences between the detected vibrations can be caused by thechanging environmental conditions instead of the object of interest. Thesystems and methods can identify these differences caused by theenvironmental conditions and modify the information that is determinedbased on the detected vibrations to account for the changes caused bythe environmental conditions. The systems and methods can thereforeself-correct changes in the vibrations that are not caused by theobjects of interest in order to improve the vitality, accuracy,precision, and functionality of the systems and methods.

Embodiments of the present invention may be used with a variety ofvehicles, including rail vehicles, mining vehicles, OHVs, automobilesand the like. The vehicles may utilize internal combustion engines,electricity, a hybrid of the two, or other power sources. The vehiclesmay be automated, self-guided or may be guided via operator input.

FIG. 1 is a schematic diagram of a vibration monitoring system 100, i.e.of a detecting system for detecting the presence of a vehicle on arailway track, according to one embodiment. The system 100 includes acontrol system 102 that generates baseline vibrations that are used todetect changing environmental conditions. The system 100 also includes asensing system 104 that detects vibrations caused by objects of interest(e.g., vibrations of interest) and the baseline vibrations. Optionally,the system 100 may include multiple sensing systems 104 that separatelydetect the vibrations of interest or the baseline vibrations.

A sensing device 106 is disposed beneath a surface 108 of the ground(e.g., the surface of the earth or another surface). In one embodiment,the sensing device 106 is a fiber optic cable that communicatesinformation between two or more locations by internally refracting lightwithin the device 106. Alternatively, the sensing device 106 may beanother type of cable that can be used to detect vibrations in theground. The sensing system 104 includes several sensors 110 (e.g.,sensors 110A-C) operably connected with the sensing device 106 atdifferent locations. For example, the sensors 110 may be light-sensitivedevices that measure changes in how light is internally reflected orotherwise refracted in the sensing device 106. The number andarrangement of the sensors 110 is provided merely as one example. Asdescribed herein, the sensing device 106 can be used to sense vibrationspropagating through the ground. Alternatively, another device, system,or apparatus may be used as the sensing device 106 to detect thevibrations. For example, one or more accelerometers, seismometers, orthe like, may sense the vibrations.

A sensing processor 112 represents one or more computer processors(e.g., microprocessors) and advantageously an associated memory,hardware circuits or circuitry, or a combination thereof, that examinedata that is output by the sensors 110 to measure the vibrationspropagating through the sensing device 106. For example, the sensors 110may be conductively coupled with the sensing processor 112 by one ormore wires, cables, or the like, and/or may be wirelessly connected withthe sensing processor 112 such that the sensors 110 can communicate datarepresentative of the vibrations detected using the sensing device 106to the sensing processor 112.

The sensing processor 112 examines the data received from the sensors110 to identify the vibrations propagating through, into, and/or aroundthe sensing device 106. Based on these vibrations and/or changes in thevibrations, the sensing processor 112 can determine information about anobject on the surface 108. This information can include anidentification of the object of interest on the surface 108, a locationof a moving object of interest on the surface 108, a moving speed of theobject of interest, a size of the object of interest, or the like. Forexample, different objects, different locations of the objects,different speeds of the objects, and/or different sizes of the objectsmay be associated with different patterns or waveforms of the vibrationsthat are determined by the sensing processor 112 and detected using thesensing device 106.

In order to account for changes in environmental conditions and theimpact of these changes in the vibrations caused by objects of interest,the control system 102 can generate baseline vibrations into the groundwhere the sensing device 106 is located. These baseline vibrations maybe generated at pre-designated times and/or during pre-designated timeperiods. The baseline vibrations may be generated with pre-designatedamplitudes and/or frequencies. As described below, these baselinevibrations may be detected by the sensing system 104 and used to modifyand correct changes to vibrations of interest that are caused byenvironmental conditions.

FIG. 2 schematically illustrates the sensing system 104 of the vibrationmonitoring system 100 shown in FIG. 1 during movement of an object ofinterest 200 according to one embodiment. The object of interest 200 isshown as a vehicle, such as a rail vehicle, automobile, mining vehicle,or the like, but alternatively may be another object. For example, thesensing device 106 can extend along a route, such as a railway track,for sensing vibrations generated by a vehicle, such as a rail vehicle,traveling along the route. During movement of the object of interest 200on or near the surface 108, vibrations of interest 202 are generated inthe ground beneath the surface 108. The vibrations of interest arevibrations that differ from baseline vibrations, as described herein.These vibrations of interest 202 propagate through the ground to thesensing device 106. The vibrations of interest 202 can change the mannerin which light is reflected within the sensing device 106. These changesare detected by the sensors 110 as changes in intensities of light,changes in intensities of light at different wavelengths, or the like.The sensors 110 output data representative of the light and/or changesin the manner in which the light is reflected within the sensing device106. This data is communicated to the sensing processor 112.

FIG. 3 illustrates one example of a frequency spectrum of vibrations ofinterest 300 generated by movement of the object of interest 200 shownin FIG. 2 as detected by the sensing system 104. The vibrations ofinterest 300 are shown alongside a horizontal axis 302 representative offrequencies of the vibrations of interest 300 and a vertical axis 304representative of amplitude or magnitude of the vibrations of interest300 at the different frequencies.

The vibrations of interest 300 can represent the vibrations detected bythe sensing system 104 during movement of the object of interest 200.These vibrations of interest 300 can represent a signature or waveformthat is associated with the object of interest 200. When the vibrationsof interest 300 are detected, the object of interest 200 can beidentified by the sensing processor 112 by comparing the vibrations ofinterest 300 to different signatures or waveforms that are associatedwith different objects of interest 200, and identifying the object ofinterest 200 based on this comparison. For example, the signatures orwaveforms may be defined as designated peaks in the vibrations ofinterest 300 that are located at designated frequencies and/or within adesignated range of frequencies. If the vibrations of interest 300 havepeaks in the designated frequencies and/or designated range offrequencies, then the vibrations of interest 300 may be identified asthe object of interest 200 that is associated with the designatedfrequencies and/or designated range of frequencies of the signature orwaveform. Optionally, different objects of interest 200 may beassociated with different signatures or waveforms, different speeds ofdifferent objects of interest 200 may be associated with differentsignatures or waveforms, different locations of objects of interest 200may be associated with different signatures or waveforms, and the like,so that the sensing system 104 may be able to identify different objectsof interest 200, different speeds of objects of interest 200, differentlocations of the objects of interest 200, and the like.

The sensing processor 112 may not be able to identify the object ofinterest 200 due to changes in environmental conditions, however. Forexample, the density, makeup, mass, or the like, of the ground maychange at different times of the day, during different seasons, andduring different weather conditions (e.g., rain, snow, ice, dry weather,etc.). These different environmental conditions can impact the manner inwhich the vibrations of interest 202 (shown in FIG. 2) propagate throughthe ground and are detected by the sensing system 104.

For example, during first environmental conditions (e.g., dry weatherduring daylight of a summer month), the vibrations of interest mayappear as the vibrations of interest 300 shown in FIG. 3. But, duringdifferent, second environmental conditions (e.g., wet weather during thenight of a spring month), the same object of interest 200 may generatethe vibrations of interest that are detected by the sensing system 104as vibrations of interest 306 in FIG. 3. During different, thirdenvironmental conditions (e.g., ice on the ground during the winter),the same object of interest 200 may generate the vibrations of interestthat are detected by the sensing system 104 as vibrations of interest308 in FIG. 3. The changing environmental conditions can prevent thesensing system 104 from being able to accurately identify the object ofinterest 200 based on the vibrations that are detected.

Returning to the description of the vibration monitoring system 100shown in FIG. 1, the system 100 can adapt to changes in theenvironmental conditions by repeatedly monitoring changes in baselinevibrations generated by the system 100 and using these changes to modify(e.g., correct) the information that is determined from the vibrationsof interest generated by the objects 200 (shown in FIG. 2). The controlsystem 102 may generate baseline vibrations 114 in the ground by movinga weighted object 116 relative to the ground. The weighted object 116can be a weight, a body with a moveable eccentric mass, or another typeof body that can generate vibrations in the ground when moved relativeto the ground. The weighted object 116 shown in FIG. 1 can be movedtoward the surface 108 of the ground to strike the ground and generatethe baseline vibrations 114. The weighted object 116 can then be movedaway from the ground for preparation in striking the ground again togenerate additional baseline vibrations 114.

The control system 102 includes a controller 118 that represents one ormore computer processors (e.g., microprocessors), hardware circuits orcircuitry, or a combination thereof. The controller 118 controlsgeneration of the baseline vibrations 114 by controlling movement of theobject 116. An actuator 120 moves the object 116 pursuant to instructionsignals received from the controller 116. The actuator 120 can include amotor, electromagnet, pneumatically controlled piston, or another devicecapable of moving the object 116 to generate the baseline vibrations114. The controller 118 generates the instruction signals andcommunicates the signals to the actuator 120 via one or more wiredand/or wireless connections. The signals can indicate the times at whichthe actuator 120 is to move the object 116 to generate the baselinevibrations 114, how long of a time period that the actuator 120 is togenerate the baseline vibrations 114, and/or how to move the object 116to generate the baseline vibrations 114. With respect to instructions onhow to move the object 116, these instructions can tell the actuator 120how high to lift the object 116 off the surface 108 before dropping ormoving the object 116 toward the surface 108, how quickly to move theobject 116 toward the surface 108 (or whether to drop the object 116onto the surface 108), how many times to move the object 116, and/or howfrequently the object 116 should be moved. If the object 116 is to bedropped onto or otherwise moved into contact with the surface 108 oranother object in contact with the surface 108 to generate the baselinevibrations 114, then the instructions can dictate how fast the object116 is moved toward the surface 108 or other object, how far the object116 is away from the surface 108 when the object 116 is dropped or movedtoward the surface 108, and the like. If the object 116 is movedrelative to the surface 108 without striking the surface 108 or anobject on the surface 108 (e.g., the object 116 is an eccentric massthat is rotated or otherwise moved relative to the surface 108 togenerate the baseline vibrations 114), then the instructions can dictatehow rapidly the object 116 is moved, how long the object 116 is moved,or the like.

FIG. 4 illustrates a frequency spectrum of baseline vibrations 400, 402,404 generated by the control system 102 shown in FIG. 1 during differentenvironmental conditions according to one embodiment. The baselinevibrations 400, 402, 404 are shown alongside the horizontal and verticalaxes 302, 304 described above in connection with FIG. 3. The baselinevibrations 400, 402, 404 are generated by the control system 102 bymoving the same object 116 (shown in FIG. 1) in the same manner, but atdifferent times and under different environmental conditions. Forexample, the baseline vibrations 400 may be sensed by the sensing system104 responsive to a ten pound (or 4.5 kilogram) object 116 being droppedonto the surface 108 (shown in FIG. 1) from one foot (or thirtycentimeters) above the surface 108 during dry conditions during thedaytime. The baseline vibrations 402, 404 may be generated and sensedduring other conditions. For example, the baseline vibrations 402 may begenerated by dropping the same ten pound (or 4.5 kilogram) object 116being onto the surface 108 from one foot (or thirty centimeters) abovethe surface 108 during rain, when there is snow on the surface 108,during nighttime, or the like. The baseline vibrations 404 may begenerated by dropping the same ten pound (or 4.5 kilogram) object 116being onto the surface 108 from one foot (or thirty centimeters) abovethe surface 108 when there is ice on the surface 108.

The control system 102 can generate the baseline vibrations atdesignated times, such as times that are known to the sensing system104. The control system 102 can generate the baseline vibrations attimes that are known or communicated to the sensing system 104 (e.g., bythe controller 118 of the control system 102 or another device) so thatthe sensing system 104 can differentiate between baseline vibrations andvibrations of interest.

In one aspect, the sensing processor 112 can determine that the system100 is malfunctioning based at least in part on the baseline vibrations.For example, the sensing processor 112 may be aware of the times atwhich the baseline vibrations are generated by the control system 102.If the sensing processor 112 does not detect the baseline vibrations attimes that correspond to when the baseline vibrations are generated,then the sensing processor 112 can determine that the system 100 ismalfunctioning. Responsive to determining this, the sensing processor112 can communicate one or more warning signals to another location,such as a repair facility, dispatch facility, or the like, to warn ofthe malfunction of the system 100, and/or to request inspection, repair,maintenance, or the like, of the system 100.

The baseline vibrations 400 can be designated as a calibrationsignature. The sensing system 104 may periodically, regularly, randomly,or otherwise repeatedly re-determine the baseline vibrations that areused as the calibration signature. Subsequently obtained baselinevibrations 402, 404 can be compared to the calibration signature inorder to determine how the vibrations sensed by the sensing system 104change, due to the changing environmental conditions. For example, thesensing system 104 can sense the baseline vibrations 402 and compare thebaseline vibrations 402 to the baseline vibrations 400 by comparingcharacteristics of the vibrations 400, 402 with each other. Thesecharacteristics can include, but are not limited to, locations (e.g.,frequencies) of peaks 406 (e.g., peaks 406A-H), widths of the peaks 406(e.g., the ranges of frequencies over which one or more peaks 406extend, heights of peaks 406 (e.g., the amplitude of one or more of thepeaks 406 along the vertical axis 304), and the like.

In the illustrated example, the sensing system 104 can compare thebaseline vibrations 400, 402 and determine that the peak 406B in thebaseline vibration 400 has moved to a lower frequency and/or has areduced amplitude as the peak 406A in the baseline vibration 402, thatthe peak 406E in the baseline vibration 400 has moved to a lowerfrequency and/or has a reduced amplitude as the peak 406D in thebaseline vibration 402, and/or that the peak 406F in the baselinevibration 400 has the same or similar frequency as the peak 406G (e.g.,is within a designated range of the peak 406F, such as 1%, 5%, 10%, orthe like) and/or has a reduced amplitude as the peak 406G in thebaseline vibration 402.

The sensing system 104 can use these differences between the baselinevibrations 400, 402 to correct the information about the objects 200that is determined from the vibrations of interest 300, 306, 308 shownin FIG. 3. For example, due to changing environmental conditions, thebaseline vibrations 400, 402 appear to shift to lower frequencies and/orhave reduced amplitudes, as described above. To correct for the impactof the changing environmental conditions on the vibrations of interest,the sensing system 104 can measure frequencies and/or amplitudes fromthe vibrations of interest, and then modify these frequencies and/oramplitudes. For example, the sensing system 104 can increase the valueof the measured frequencies at which peaks appear in the vibrations ofinterest 300, 306, 308, can increase the value of the amplitudes of thepeaks in the vibrations of interest 300, 306, 308, or the like. Thefrequencies and/or amplitudes of the peaks in the vibrations of interest300, 306, 308 can be increased by the same amount that the frequenciesand/or amplitudes of the peaks in the baseline vibrations 400, 402decreased, or may be increased by an amount that is at least partiallybased on the decrease in the peaks in the baseline vibrations 400, 402.While the sensing system 104 may not be actually changing thefrequencies, amplitudes, or the like, of the peaks, the sensing system104 can change the measured frequencies, amplitudes, or the like, thatare measured from the vibrations of interest and used to identifyinformation about the object 200.

As another example, the sensing system 104 can compare the baselinevibrations 400, 404 and determine that the peak 406B in the baselinevibration 400 has moved to a higher frequency and/or has a reducedamplitude as the peak 406C in the baseline vibration 404, and/or thatthe peak 406F in the baseline vibration 400 has moved to a higherfrequency and/or has an increased amplitude as the peak 406H in thebaseline vibration 404. The sensing system 104 can use these differencesbetween the baseline vibrations 400, 404 to correct informationdetermined from the vibrations of interest 300, 306, 308 shown in FIG.3. For example, due to changing environmental conditions, the baselinevibrations 400, 402 appear to shift to higher frequencies and/or haveincreased amplitudes, as described above. To correct for the impact ofthe changing environmental conditions on the vibrations of interest, thesensing system 104 can modify the frequencies and/or amplitudes that aremeasured from the vibrations of interest. For example, the sensingsystem 104 can decrease the frequencies at which peaks appear in thevibrations of interest 300, 306, 308, can decrease the amplitudes of thepeaks in the vibrations of interest 300, 306, 308, or the like. Thefrequencies and/or amplitudes of the peaks in the vibrations of interest300, 306, 308 can be decreased by the same amount that the frequenciesand/or amplitudes of the peaks in the baseline vibrations 400, 404increased, or may be decreased by an amount that is at least partiallybased on the increase in the peaks in the baseline vibrations 400, 404.

In one embodiment, the sensing system 104 can determine informationabout the environmental conditions based on the differences between thebaseline vibrations. For example, based on decreases in frequency forone or more peaks in the baseline vibrations, the sensing system 104 candetermine that the ground is becoming softer, such as due to rainfall.Alternatively, based on increases in frequency for one or more peaks inthe baseline vibrations, the sensing system 104 can determine that theground is becoming harder, such as due to ice forming on and/or in theground. The sensing system 104 can use this information about theenvironmental conditions to change vibrations of interest, as describedabove. Additionally or alternatively, the sensing system 104 can use theinformation about the environmental conditions to warn operators ofvehicles of dangerous conditions. For example, the sensing system 104can generate signals that are communicated to vehicles to warn thevehicles of potential ice, rain, or the like, that the sensing system104 may have detected.

Once the information determined from the vibrations of interest iscorrected, the vibrations of interest can be referred to as corrected ormodified vibrations of interest. For example, a waveform, measuredfrequency of a peak, measured amplitude of a peak, or the like, in thevibration of interest may be corrected by changing the measuredwaveform, measured frequency, and/or measured amplitude to a modifiedwaveform, frequency and/or amplitude. This corrected or modifiedinformation can be compared to the signatures or waveforms associatedwith different objects of interest. Depending on which signatures orwaveforms more closely match or otherwise correspond to the corrected ormodified information, the sensing system 104 may be able to identify theobject of interest, the speed of the object of interest, the location ofthe object of interest, the size of the object of interest, or the like,based at least in part on the corrected or modified information. Theidentified object, speed, location, size, or the like can be used for avariety of purposes, such as to activate a warning system or signal thata vehicle is approaching, to determine if a vehicle is traveling toofast or too slow, to generate control signals that automatically slowdown or speed up the vehicle based on the speed that is determined, orthe like. For example, based on the corrected information, the sensingsystem 104 can determine a size of a moving vehicle, the location of thevehicle, and/or how fast the vehicle is moving. The size of the vehiclemay be used by the sensing system 104 to differentiate between differentvehicles and thereby identify the vehicle. Based on the location of thevehicle and the speed of the vehicle, the sensing system 104 cangenerate control signals that are communicated to one or more locations,such as a dispatch center, where the identify, location, and/or speed ofthe vehicle can be displayed to one or more operators to monitormovements of the vehicle. Optionally, these control signals may becommunicated to a signal (e.g., a light or a gate) to actuate the signaland warn other vehicles of the movement of the detected vehicle.

FIG. 5 illustrates a flowchart of a method 500 for monitoring vibrationsaccording to one embodiment. The method 500 can be performed by themonitoring system 100 shown in FIG. 1 and described above. At 502,vibrations are sensed. For example, vibrations propagating through theground may be detected. The vibrations can be sensed by examiningchanges in light being conveyed through a cable, such as a fiber opticcable. Alternatively, the vibrations may be sensed in another manner,such as by using one or more accelerometers or other devices. At 504, adetermination is made as to whether the sensed vibrations are baselinevibrations. The baseline vibrations may be generated at known ordesignated times, or within known or designated time periods. If thevibrations are sensed at the known or designated times, within adesignated time period following the known or designated times (e.g.,within thirty seconds or another time period), within the known ordesignated time periods, or the like, then the sensed vibrations may beidentified as baseline vibrations. As a result, flow of the method 500can proceed to 506. On the other hand, if the sensed vibrations are notsensed at times that would correspond with the generation of thebaseline vibrations, then flow of the method 500 can proceed to 512,which is described below.

At 506, the baseline vibrations are examined for changes from one ormore previous baseline vibrations. For example, the baseline vibrationssensed at 502 can be compared with previously sensed baseline vibrationsto determine if shapes, waveforms, peaks, or the like, in the previouslysensed baseline vibrations have moved (e.g., changed which frequenciesthe peaks appear at), changed shape (e.g., have larger or smalleramplitudes, are wider or narrower, etc.), or otherwise changed.

At 508, a determination is made as to whether the baseline vibrationshave changed. If the baseline vibrations have changed from one or morepreviously sensed baseline vibrations, then environmental conditions maybe altering the propagation of vibrations through the ground. As aresult, the vibrations generated by objects of interest also may bealtered by the environmental conditions in a similar manner. If thebaseline vibrations have changed or have changed by at least asignificant amount (e.g., the frequency of a peak changes by at least adesignated, non-zero amount, such as 1%, 5%, 10%, or another amount),then flow of the method 500 can proceed to 510. On the other hand, ifthe baseline vibrations have not changed, or have not changed by asignificant amount, then flow of the method 500 can proceed to 512,which is described below.

At 510, corrections to sensed vibrations are determined from the changesin the baseline vibrations. For example, the change in the frequenciesat which one or more peaks appear in the baseline vibrations, the changein amplitudes of the peaks, or other changes, may be calculated. At 512,vibrations of interest are sensed. If the vibrations sensed at 504 arenot baseline vibrations, then the sensing of vibrations at 504 and 512may be the same operation of sensing the same vibrations. Because thevibrations are not baseline vibrations used to determine corrections toaccount for changing environmental conditions, the vibrations may bevibrations of interest. These vibrations may be used to identify anobject of interest, speed of the object of interest, a location of theobject of interest, or the like.

At 514, the vibrations of interest are corrected based on thecorrections determined from the baseline vibrations. For example, one ormore frequencies, amplitudes, waveforms, or the like, that aredetermined from the vibrations of interest can be modified based on thecorrections determined from the baseline vibrations. If no correctionswere determined based on changes in the baseline vibrations (e.g., thebaseline vibrations were not affected by the environmental conditions orwere not significantly affected such that one or more peaks did notshift frequencies and/or change amplitudes by at least a designated,non-zero amount), then the information obtained from the vibrations ofinterest may not be modified. On the other hand, if corrections weredetermined based on changes in the baseline vibrations, then thesecorrections may be applied to the information determined from thevibrations of interest to form corrected or modified information fromthe vibrations of interest.

At 516, the corrected vibrations of interest (or vibrations of interestthat were not corrected due to the lack of significant changes to thebaseline vibrations) are compared to one or more designated signaturesor waveforms. As described above, different signatures or waveforms mayinclude different patterns, arrangements, or the like, of peaks, and maybe representative of different types of objects of interest, differentmoving speeds of different objects of interest, different locations ofobjects of interest, etc.

At 518, a determination is made as to whether the corrected vibrationsof interest (or vibrations of interest that were not corrected due tothe lack of significant changes to the baseline vibrations) match one ormore of the signatures or waveforms. For example, a determination may bemade as to whether the peaks or other shapes of the frequency spectrumof the corrected vibrations of interest more closely match the peaks orother shapes of a signature or waveform than one or more othersignatures or waveforms. If so, then flow of the method 500 can proceedto 520. For example, the corrected vibrations of interest may closelymatch the peaks of a signature or waveform representative of aparticular object of interest, a particular speed of an object ofinterest, a particular location of an object of interest, or the like.On the other hand, if the corrected vibrations of interest do not matchone or more of the signatures or waveforms, then the vibrations ofinterest may not represent an object of interest, a speed of an objectof interest, a location of an object of interest, or the like. As aresult, flow of the method 500 can return to 502 for additionalvibrations to be sensed.

At 520, information about an object of interest is determined based atleast in part on the vibrations of interest. For example, the object ofinterest, the location of the object of interest, the speed of theobject of interest, or the like, that is associated with a signature orwaveform that more closely matches the corrected vibrations of interestthan other signatures or waveforms may be identified. After thisidentification, flow of the method 500 can return to 502 so thatadditional vibrations can be sensed, corrected, and/or used to identifyinformation about an object of interest.

Returning to the description of the vibration monitoring system 100shown in FIG. 1, the system 100 can adapt to changes in the location ofthe sensing device 106 and/or other components of the sensing system 104by continuously and repeatedly verifying integrity of the sensing devicesignals. Accordingly, in another aspect, the system 100 may also includea calibration device 122 that is placed in the vicinity of the sensingdevice 106 and which can be utilized by the system 100 as a vital way toensure that movements in either the calibration device 122 or thesensing device 106 and/or other components of the sensing system 104 aredetected and accounted for. The calibration device 122 may interfacewith a wayside bungalow 124 containing communication equipment thatrelays health information of the calibration device 122 to the sensingprocessor 112. While the calibration device 122 and wayside bungalow 124are illustrated as being separate from control system 102, in anembodiment, the calibration device 122 and wayside bungalow 124,including the communication equipment contained therein, may beintegrated with the control system 102. By integrating the calibrationdevice and communication equipment with the control system 102,duplication of components performing related functions may be obviated.

In one embodiment, the calibration device 122 includes an acousticdevice configured to generate and amplify an analog tone 126 thatpropagates, through air and/or sub-terrain, to the sensing device 106,and is utilized as a regular calibration or reference point, asdiscussed hereinafter. The acoustic device may be, for example, a lowfrequency acoustic transducer that is configured to impart a lowfrequency acoustic signal (e.g., 1 to 30 Hz) to ground or otherwise.Alternatively or additionally, the acoustic device may utilize so-calledground penetrating sonar, such as described in U.S. Pat. No. 5,719,823,issued Feb. 17, 1998 and incorporated by reference herein in itsentirety. Part of the acoustic device may be buried in the groundsurface to facilitate transmission of acoustic energy from the device tosoil. Additionally, soil around the buried portion may be made uniformor otherwise augmented to facilitate transfer of acoustic energy fromthe buried portion to non-augmented soil in which the fiber optic cableis buried.

The calibration device 122 may be installed on a moving platform orfixed anywhere along the wayside route and provides a reference point orlocation point through either a mile post marking, survey marker, GPS,or other known reference point. The exact location of the calibrationdevice 122 is stored by the sensing processor 112 as a repeatablereference point and verified as needed for system integrity checking.Once calibrated, a window threshold may be set and, when exceeded, thesystem 100 will be alerted that the sensing device 106 has moved or thecalibration device 122 has moved or is being interfered with. In anembodiment, the calibration device 122 may send a continuous signal tothe sensing device 106. In other embodiments, the calibration device 122may output the reference tone 126 at defined intervals.

In particular, in one embodiment, the calibration device 122 may have anon-board, real-time precision clock 128. Embedded software/firmwareutilizes the on-board clock 128 to energize the acoustic output atdefined intervals. The device 122 has communication abilities, whichallow for the syncing of the device 122 with a wayside location or tothe back office to ensure drift of the clock 128 is accommodated.

In another embodiment, the calibration device 122 receives communicationprotocol at regular intervals in the event that the system 100 needs toverify the accuracy and location of the device 122. The calibrationdevice 122 will then generate the analog signal, and report back to thesensor processor 112 once it has generated the signal. The sensorprocessor 112 will then confirm that a signal was received both from thesensors 110 as well as the status from the calibration device 122 toconfirm the output was successfully energized.

In the event that the sensing device 106 is moved, and to prevent afalse positive signal from the calibration device 122 to the sensingdevice 106, the calibration device 122 is provided as a constant poweroutput device that monitors the output signal 126 and ensures that afailure mode of the device does not falsely output an increase in energyor signal level such that the sensing device 106 will detect thereference signal from a greater distance away.

The calibration device 122 may be arranged within a housing (not shown)capable of withstanding the harsh environment of an external wayside(e.g., rail) location. In certain embodiments, the calibration device122 accepts either standard DC or AC input to energize the device usingcommon connector types such as Wago or Phoenix, and has the ability tocommunicate either fiber optically or over Ethernet back to a waysidebungalow 126 or back office to report the status of the device 122 as aform of health indication and monitoring.

FIG. 6 illustrates a flowchart of a method 600 for verifying theintegrity of the sensing system 104. The method 600 can be performed bythe monitoring system 100 shown in FIG. 1 and described above. At 602,the sensing processor 112 continuously monitors the sensing device 106for signals, in the manner described above, to determine vehiclemovement or for calibration information generated by the calibrationdevice 122. At step 604, the calibration device outputs an analog signalto be received by the sensing device 106 at a given location. At step606, the sensing processor 112 receives the signal generated by thecalibration device 122 through the sensing device 106. The sensingprocessor 112, at step 608, then verifies that the signal level of thereceived signal is within a predetermined threshold, which signifiesthat the calibration device 122 and the sensing device 106 have notmoved.

FIG. 7 illustrates a flowchart of a method 700 for determining thelocation status of the calibration device 122. The method 700 can beperformed by the monitoring system 100 shown in FIG. 1 and describedabove. At step 702, the calibration device 122 may utilize GPS or othertime-based location to determine status. Mile post may also beprogrammed into the calibration device 122. At step 704, the calibrationdevice 122 syncs with the sensing processor 112 or wayside equipment toconfirm date, time and location. At step 706, the acoustic signal sentthrough the sensing device 106 is utilized to verify that the sensingdevice (i.e., the fiber optic cable) has not moved and the calibrationdevice 122 has not moved. If the sync does not occur or the sensingprocessor 112 determines that the signal level is unacceptable (e.g.,outside of a predefined threshold window), the sensing processor 112will alert the system 100, at step 708, that the calibration device 122cannot be trusted.

As discussed above, to ensure the safety integrity level is maintainedand the calibration device 122 has not been relocated, the calibrationdevice 122 includes a form of self-location, such as GPS or othertime-based synchronization system similar to that contained in aircraftnavigation systems. This self-location information may be communicatedeither to the fiber interrogation equipment (i.e., the sensing processor112) or stored in the sensing processor 112 which will validate thereported position versus the allowable position. This will providenotification in the instance that the calibration device 122 has beenmoved to maintain vitality of the system 100.

In one embodiment, a system includes an acoustic device that outputs ananalog signal to a fiber cable for calibration and locationverification. The acoustic device utilizes GPS or communication fromwayside bungalow equipment to verify GPS location or real-time clockinformation. The wayside bungalow contains communication equipment thatinterfaces with the acoustic device and relays health information to asensing processor. The sensing processor is configured to detect theacoustic signal output by the acoustic device at a known location andverifies that the cable and device have not moved location by comparingthe signal level received against a threshold stored in memory. When thethreshold is exceeded, the sensing processor sends an alert that thefiber optic cable or acoustic device at the location have changed.

FIG. 8 is a schematic diagram of a vibration monitoring system 800, i.e.of a detecting system for detecting the presence of a vehicle on arailway track, according to one embodiment. The detecting system 800includes a control system 802 configured for generating and emittingsignals into the ground 808. The signals correspond for example tovibrations produced into the ground and/or to analog tones. The signalscorrespond notably to baseline vibrations that are used to detectchanges in environmental conditions and/or initialization vibrationsthat are used to initialize a sensing system 804 of the detectingsystem, and/or analog tones that propagate, through air and/orsub-terrain, to the sensing system 804 and are utilized as a regularcalibration or reference point.

The sensing system 804 is adapted for detecting vibration into groundand notably for detecting vehicles circulating on the track inducingsecond signals, i.e. vibrations of interest, also called second signals.

The sensing system 804 is also adapted for detecting first, third andfourth signals corresponding respectively to initialization vibrationsV1 that are used to initialize the sensing system 804, analog tones usedto detect if the control system or the sensing system has moved in anunexpected manner, baseline vibrations V2 that are used to detectchanges in environmental conditions.

The sensing system 804 comprises a sensing device 806 and sensors 810(810A, 810B, 810C) comprising respectively the same elements, arrangedin a same manner, than the sensing system 104 and the sensing device106, described above in the first embodiment described.

The sensing system 804 is associated with a sensing processor 812, alsocalled sensing module, monitoring the sensing system 804, the sensingprocessor comprising the same elements, arranged in a same manner, thanthe sensing processor 112, described above in the first embodimentdescribed.

The control system 802 comprises a controller 822 that represents one ormore computer processors (e.g., microprocessors), hardware circuits orcircuitry, or a combination thereof, which is associated with a centralmemory 824.

Advantageously the controller 822 is adapted for executing softwareprogramming instructions comprised in the central memory 824.

The control system 802 comprises a moving object 830 adapted forgenerating vibrations into the ground and notably baseline vibrations V1that are used to detect changes in environmental conditions of the trackand initialization vibrations V2 that are used to initialize the sensingprocessor 812.

The control system 802 comprises an actuator 832 configured forcontrolling the movement of the moving object 830. Advantageously, theactuator comprises two functioning mode a track configuration mode inwhich it commands the moving object to emit the first signalcorresponding to the initialization vibrations V1 and a supervision modein which it commands the moving object to emit the fourth signalcorresponding to the baseline vibrations V2.

The control system 802 comprises also a communication device 836 adaptedfor communicating data and notably exchanging messages with the sensingprocessor 812 and a calibration device 838 corresponding to thecalibration device 122 described above. The calibration device 838 isadapted for sending the third signal corresponding to an analog tone T1that propagates, through air and/or sub-terrain, to the sensing system804 and is utilized as a regular calibration or reference point.

Advantageously the control system 802 comprises a localization device839, such as a GPS device, adapted for determining the position of thecontrol system 802.

The control system 802 is preferably movable and mounted on wheels, inorder that an operator can move the control system 802 along the railwaytrack.

Advantageously the control system 802 is adapted to be taken off thewheels and installed along the track close to a sensing system 804 afterthe initialization of the sensing processor 812.

The sensing processor 812 comprises a detection module 840 for detectinga vehicle on the railway track, a configuration device 842 adapted forconfiguring the detection module 840, a security module 844 to determineif at least one of the calibration device 838 or the sensing device 806has moved and a control module 846 adapted for supervising changes inthe environmental conditions of the sensing system 804.

The central memory 824 comprises initialization programming instructions850 and controlling programming instructions 856.

The initialization programming instructions 850 and the controller 822form with the moving object 830, the actuator 832 and the communicationdevice 836 an initialization device.

The initialization programming instructions 850 are configured, whilethey are executed, to command the actuator 832, to emit the first signalinto the ground 808 towards the sensing processor 812 through thesensing device 806, which is for example a fiber optic cable.

The initialization programming instructions 850 are also configured,while they are executed, to generate a first message comprisingconfiguration data chosen among, location of the initialization device,intensity/magnitude of the first signal, emission time of the firstsignal and type of objects corresponding to the first signal, and tocommand the sending of the first message to the sensing processor 812through the communication device 836.

Advantageously, the configuration data comprise at least the firstsignal intensity/magnitude.

Preferentially, the initialization programming instructions 850 areconfigured for commanding the emission of the first signal and thesending of the first message approximately simultaneously.

Advantageously, the controller 822 is adapted for executing theinitialization programming instructions 850 several times for a givenlocation of the control system 802, in order to successively emitdifferent first signals having different intensity levels. Theinitialization programming instructions 850 are for example executed atpredetermined time intervals, or each time an activator on the controlsystem is activated, or when the initialization device is not moving fora predetermined amount of time.

The fact that the control system 802 can send the first signal at timesthat are known to the sensing system 804 and notably communicated to thesensing system 804 allows to differentiate first signals from othersignals.

The controlling programming instructions 856 are configured, while theyare executed, to command the actuator 832, to send the fourth signalinto the ground towards the sensing processor 812 through the sensingdevice 806 which is for example a fiber optic cable.

The controlling programming instructions 856 are also configured, whilethey are executed, to generate a second message comprising control datachosen among, location of the control system 802, intensity/magnitude ofthe fourth signal, emission time of the fourth signal, and to commandthe sending of the second message to the sensing processor 812 throughthe communication device 836.

Preferentially, the controlling programming instructions 856 areconfigured for commanding the emission of the fourth signal and thesending of the second message approximately simultaneously.

Advantageously, the fourth signal is outputted at predetermined timesand/or during predetermined time periods, the fourth signal havingadvantageously a predetermined amplitude, i.e. intensity/magnitude,and/or frequency.

The fact that the control system 802 can send the fourth signal at timesthat are known to the sensing system 804 and notably communicated to thesensing system 804 and with specific amplitude and/or frequency allowsto differentiate fourth signals from other signals.

The calibration device 838 is configured for outputting the third signaltowards the sensing processor 812 through the sensing device 806.

Advantageously the intensity/magnitude of the third signal ispredetermined for a given location of the control system and the sensingprocessor.

The calibration device 838 includes an acoustic device 860 configured togenerate and amplify the analog tone that propagates, through air and/orsub-terrain, to the sensing device, and is utilized as a regularcalibration or reference point, as discussed hereinafter. The acousticdevice may be, for example, a low frequency acoustic transducer that isconfigured to impart a low frequency acoustic signal (e.g., 1 to 30 Hz)to ground or otherwise. Alternatively or additionally, the acousticdevice may utilize so-called ground penetrating sonar, such as describedin U.S. Pat. No. 5,719,823, issued Feb. 17, 1998 and incorporated byreference herein in its entirety. Part of the acoustic device may beburied in the ground surface to facilitate transmission of acousticenergy from the device to soil. Additionally, soil around the buriedportion may be made uniform or otherwise augmented to facilitatetransfer of acoustic energy from the buried portion to non-augmentedsoil in which the fiber optic cable is buried.

The calibration device 838 is adapted for providing a reference point orlocation point to the sensing processor thanks to the localizationdevice 839 and the communication device 836. The exact location of thecalibration device is stored by the sensing processor as a repeatablereference point and verified as needed for system integrity checking.For example, the calibration device 838 is adapted for sending to thesensing processor 812 the position of the control system 802 determinedby the localization device 839. Once calibrated, a window threshold maybe set in the sensing processor 812 and, when intensity/magnitude levelof the third signal exceeded, the security module 844 is adapted todetermine that the sensing device has moved or the calibration devicehas moved or is being interfered with. The window threshold may dependon the control system position sent by the control system 802. In anembodiment, the calibration device 838 may send the third signalcontinuously to the sensing device 806. In other embodiments, thecalibration device 838 may output the third signal, i.e. the referencetone at defined intervals and approximately at the same time send thelocation of the control system 802 to the sensing processor 812.

Advantageously, the frequency of the third signal is not comprised inthe frequency spectrum of the first and fourth signals so that thesensing processor 812 can differentiate the three signals.

More advantageously, the first, third and fourth signals are emitted attimes that are known or communicated to the sensing processor 812 (e.g.,by the control system 802) and with predefined frequency spectrum andintensity/magnitude intervals so that the sensing processor 812 candifferentiate between first, third, fourth signals and second signals,corresponding to a second signal induced by a vehicle moving on thetrack close to the sensing system 804.

The configuration device 842 is adapted for configuring the detectionmodule 840 in function of the received first signal and the receivedconfiguration data.

The configuration device 842 is notably adapted for memorizing in acomparison unit 870 of the detection module 840 a set of measured datarelative to the received first signal and to associate to the memorizedset of measured data the received configuration data.

Advantageously when the configuration device 842 received several firstsignals having the same intensity and sent from the same location itdetermines the set of measured data to memorize in function of thedifferent first signals received, by performing for example an averagingalgorithm.

Advantageously in the comparison unit 870, the memorized set of measureddata is associated with a type of detected object, according to thesignal intensity comprised in the associated configuration data andpreferentially is associated also with a location of the type ofdetected object determined in function of the location of theinitialization device comprised in the configuration data.

The comparison unit 870 memorizes, for example, a set of measured datafor each first signal received having a different value of signalintensity comprised in the associated configuration data and/or adifferent location comprised in the associated configuration data.

The sensing processor 812 and notably the comparison unit 870 isconfigured for comparing a received second signal, generated by anobject moving near the sensing processor, with each memorized set ofmeasured data in order to determine a type of detected objectcirculating on the railway track and preferentially also its location.

More advantageously, the memorized set of measured data is relative to ageneral form of the first signal monitored by the sensing processor 812through the sensing device 806 and corresponds to a signal signature orwaveform which is associated with a type of detected object, notably infunction of the signal intensity/magnitude comprised in the associatedconfiguration data. The signatures or waveforms may be defined asdesignated peaks that are located at designated frequencies and/orwithin a designated range of frequencies. If the vibrations of interest,i.e. the second signals, have peaks in the designated frequencies and/ordesignated range of frequencies, then the vibrations of interest may beidentified as the object of interest that is associated with thedesignated frequencies and/or designated range of frequencies of the setof measured data. Optionally, different objects of interest may beassociated with different set of measured data, different speeds ofdifferent objects of interest may be associated with different set ofmeasured data, different locations of objects of interest may beassociated with different set of measured data, and the like, so thatthe sensing system 804 and notably the detection module 840 may be ableto identify different objects of interest, different speeds of objectsof interest, different locations of the objects of interest, and thelike comparing second signals with memorized sets of measured data.

Depending on which set of measured data, i.e. signatures or waveformsmore closely match or otherwise correspond to the received secondsignal, the sensing processor 812 may be able to identify the object ofinterest, the speed of the object of interest, the location of theobject of interest, the size of the object of interest, or the like.

The security module 844 is adapted for comparing the third signalamplitude with a window threshold to determine if at least one of thecalibration device or the sensing device 806 has moved. When intensitylevel of the third signal exceeds the window threshold, the securitymodule 844 is adapted to determine that the sensing device has moved orthe calibration device has moved or is being interfered with.

The calibration device 838 and the security module are, for example,adapted for implementing the method 700.

The control module 846 is adapted for supervising changes in theenvironmental conditions of the sensing system 804. The control module846 is notably configured for comparing the received fourth signal withpre-memorized data in order to detect changing in environmentalconditions of the railway track.

The control module 846 is adapted for amending the memorized set ofmeasured data or data relative to a received second signal in functionof the detected changes in environmental conditions of the railwaytrack. The control module 846 is adapted to obtain information aboutenvironmental conditions and detect changes as described for the sensingprocessor 112 above. The baseline vibrations 400 can be for exampledesignated as a calibration signature. The sensing processor 812 mayperiodically, regularly, randomly, or otherwise repeatedly re-determinethe baseline vibrations that are used as the calibration signature.Subsequently obtained baseline vibrations 402, 404 through sensingdevice 806 can be compared to the calibration signature in order todetermine how the vibrations sensed by the sensing system 804 change dueto the changing environmental conditions. For example, the controlmodule 846 can sense the baseline vibrations 402 and compare thebaseline vibrations 402 to the baseline vibrations 400 by comparingcharacteristics of the vibrations 400, 402 with each other. Thesecharacteristics can include, but are not limited to, locations (e.g.,frequencies) of peaks 406 (e.g., peaks 406A-H), widths of the peaks 406(e.g., the ranges of frequencies over which one or more peaks 406extend, heights of peaks 406 (e.g., the amplitude of one or more of thepeaks 406 along the vertical axis 304), and the like.

In one embodiment, the control module 846 is adapted for amending areceived second signal, induced by a vehicle moving on the track closeto the sensing system 804, in function of the detected changes inenvironmental conditions of the railway track.

The control module 846 can use differences between the baselinevibrations 400, 402 to correct data relative to received second signals,that are determined from the vibrations of interest 300, 306, 308 shownin FIG. 3. For example, due to changing environmental conditions, thebaseline vibrations 400, 402 appear to shift to lower frequencies and/orhave reduced amplitudes, as described above. To correct for the impactof the changing environmental conditions on the vibrations of interest,the control module 846 can measure frequencies and/or amplitudes fromthe vibrations of interest, and then modify these frequencies and/oramplitudes. For example, the control module 846 can increase the valueof the measured frequencies at which peaks appear in the vibrations ofinterest 300, 306, 308, can increase the value of the amplitudes of thepeaks in the vibrations of interest 300, 306, 308, or the like. Thefrequencies and/or amplitudes of the peaks in the vibrations of interest300, 306, 308 can be increased by the same amount that the frequenciesand/or amplitudes of the peaks in the baseline vibrations 400, 402decreased, or may be increased by an amount that is at least partiallybased on the decrease in the peaks in the baseline vibrations 400, 402.

The control module 846 can repeatedly monitoring changes in baselinevibrations generated by the control system 802 to monitor changes in theenvironmental conditions and using these changes to modify (e.g.,correct) the information that is determined from the vibrations ofinterest generated by an object 200 circulating close to the sensingsystem 804.

In one aspect, the control module 846 is configured to determine thatthe system 100 is malfunctioning based at least in part on the baselinevibrations. For example, the sensing control module 846 may be aware ofthe times at which the baseline vibrations are generated by the controlsystem 802. If the control module 846 does not detect the baselinevibrations at times that correspond to when the baseline vibrations aregenerated, then the control module 846 can determine that the system 800is malfunctioning. Responsive to determining this, the sensing processor812 can communicate one or more warning signals to another location,such as a repair facility, dispatch facility, or the like, to warn ofthe malfunction of the system 800, and/or to request inspection, repair,maintenance, or the like, of the system 800.

As a variant, the initialization programming instructions 850 areconfigured, while they are executed, to command the actuator 832, toemit successively several first signals having the same intensitylevels, while the control system stays preferably at the same location.In this variant the memorized set of measured data are determined byusing averaging algorithm for example.

As a variant, the control system 802 is devoid of calibration device andthe actuator comprises only one functioning mode which is the trackconfiguration mode. In this variant after the initialization of thesensing processor 812, control systems 102 are installed along the trackfor each sensing system 804 and functions has described in the firstembodiment described above. In this variant, the memorized sets ofmeasured data correspond to the designated signatures or waveforms ofFIG. 5.

FIG. 9 illustrates a flowchart of the steps of a method for detectingthe presence of a vehicle on a railway track realized by the detectingsystem 800.

First, the method comprises an initialization step 900, then after thefinalization of the initialization step the method comprises, a securitystep 902, a control step 904 and a detecting step 906.

The initialization step is presented in more details on FIG. 10. Theinitialization step comprises:

-   -   an emission sub-step 900A, during which, the controller executes        the initialization programming instructions 850 in order to emit        the first signal;    -   a sending sub-step 900B, the controller 822 executing the        initialization programming instructions 850 in order to send the        first message to the sensing processor 812;    -   a monitoring sub-step 900C, the sensing processor 812 monitoring        the sensing system; and    -   a configuring sub-strep 900D, during which the configuration        device 842 configures the detection module 840 in function of        the received first signal and the received configuration data.        More especially, a set of measured data relative to the received        first signal are memorized and are associated with the        configuration data and notably with a type of detected object,        according to, for example, the signal intensity comprised in the        associated configuration data. Preferentially the memorized set        of measured data is associated also with a location of the type        of detected object determined in function of the location of the        control system 802 comprised in the configuration data.

During the initialization step the actuator 832 is configured in thetrack configuration mode.

After the initialization, step the sensing processor 812 is initializedand is configured for detecting objects moving on the track close to thesensing system 804. Advantageously, after the initialization step thecontrol system 802 is taken off the wheels and installed close to thesensing system 804 at a predetermined location.

After the initialization step the actuator 832 is configured in thesupervision mode.

Advantageously, the initialization step 900 is repeated: atpredetermined time intervals, or each time an activator on theinitialization device is activated, or when the initialization device isnot moving for a predetermined amount of time.

Advantageously the control system 802 is moved along the track atpredetermined locations and the initialization step 900 is repeatedseveral times with first signals having different intensity levels,corresponding to different type of objects, such as a car, an animal, atrain, a road vehicle . . .

The security step 902 is presented in more details on FIG. 11. Thesecurity step 902 comprises:

-   -   a sending sub-step 902A, during which the calibration device        output the third signal;    -   a monitoring sub-step 902B, the sensing processor monitoring the        sensing system; and    -   a determining step 902C, during which the security module        compares the third signal amplitude with a window threshold to        determine if at least one of the calibration device or the        sensing device 806 has moved. When intensity level of the third        signal exceeds the window threshold, the security module 844        determines that the sensing device has moved or the calibration        device has moved. Thus, this determining sub-step includes        verifying if at least one of the calibration device or sensing        system has moved.

Advantageously, when the window threshold is exceeded, the sensingprocessor 812 sends an alert, that the fiber optic cable or acousticdevice at the location have changed, to a supervision central of therailway track.

The control step 904 is presented in more details on FIG. 12. Thecontrol step 904 comprises:

-   -   an emitting sub-step 904A, during which the control system 802        output the fourth signal;    -   a sending sub-step 904B, the control system 802, sending to the        sensing processor 812, a second message comprising control data        chosen among, location of the control device,        intensity/magnitude of the fourth signal, emission time of the        fourth signal;    -   a monitoring sub-step 904C, the sensing processor monitoring the        sensing system;    -   a modifying sub-step 904D, during which the sensing processor        modifies the memorized set of measured data or measured data        relative to a received second signal in function of the received        fourth signal. During the modifying sub-step the sensing        processor compares the received fourth signal with pre-memorized        data in order to detect changing in environmental conditions of        the railway track, then at least one of the memorized set of        measured data or measured data relative to the received second        signal being modified in function of the detected changes in        environmental conditions of the railway track.

The detecting step 906 is presented in more details on FIG. 13. Thedetecting step 906 comprises:

-   -   a commissioning step 906A, during which an object, notably a        train, moves on the track close to the sensing system; The        movement of the train induces vibrations corresponding to a        second signal measured by the sensing system,    -   a monitoring sub-step 906B, the sensing processor monitoring the        sensing system; and    -   a determination sub-step 906C, during which the sensing        processor compares the received second signal with each        memorized set of measured data in order to determine a type of        detected object circulating on the railway track and        preferentially also its location.

Advantageously, before the determination sub-step, the control step 904is realized to amend the measured data relative to a received secondsignal in function of detected changes in environmental conditions.

At step 904C, for example, a determination may be made as to whether thepeaks or other shapes of the frequency spectrum of the vibrations ofinterest more closely match the peaks or other shapes of a signature orwaveform than one or more other signatures or waveforms. For example,the corrected vibrations of interest may closely match the peaks of asignature or waveform representative of a particular object of interest,a particular speed of an object of interest, a particular location of anobject of interest, or the like. On the other hand, if the correctedvibrations of interest do not match one or more of the signatures orwaveforms, then the vibrations of interest may not represent an objectof interest, a speed of an object of interest, a location of an objectof interest, or the like. then, flow of the method can return to 906Aand 906B for additional vibrations to be sensed.

At step 904C, information about an object of interest is determinedbased at least in part on the vibrations of interest. For example, theobject of interest, the location of the object of interest, the speed ofthe object of interest, or the like, that is associated with a signatureor waveform that more closely matches the corrected vibrations ofinterest than other signatures or waveforms may be identified.

Therefore, it appears that the control step 904 impact the detectingstep 906 and allows to adapt the detecting step to changes inenvironmental conditions of the railway track.

Clearly, the principle of the invention remaining the same, theembodiments and the details of production can be varied considerablyfrom what has been described and illustrated purely by way ofnon-limiting example, without departing from the scope of protection ofthe present invention as defined by the attached claims.

Components of the systems described herein may include or representhardware circuits or circuitry that include and/or are connected withone or more processors, such as one or more computer microprocessors.The operations of the methods described herein and the systems can besufficiently complex such that the operations cannot be mentallyperformed by an average human being or a person of ordinary skill in theart within a commercially reasonable time period. For example, theexamination of the vibrations may take into account a large amount ofinformation, may rely on relatively complex computations, and the like,such that such a person cannot complete the examination of thevibrations within a commercially reasonable time period to correctvibrations measured during passage of a vehicle. The hardware circuitsand/or processors of the systems described herein may be used tosignificantly reduce the time needed to obtain and examine thevibrations.

As used herein, a structure, limitation, or element that is “configuredto” perform a task or operation is particularly structurally formed,constructed, programmed, or adapted in a manner corresponding to thetask or operation. For purposes of clarity and the avoidance of doubt,an object that is merely capable of being modified to perform the taskor operation is not “configured to” perform the task or operation asused herein. Instead, the use of “configured to” as used herein denotesstructural adaptations or characteristics, programming of the structureor element to perform the corresponding task or operation in a mannerthat is different from an “off-the-shelf” structure or element that isnot programmed to perform the task or operation, and/or denotesstructural requirements of any structure, limitation, or element that isdescribed as being “configured to” perform the task or operation.

It is to be understood that the above description is intended to beillustrative, and not restrictive. For example, the above-describedembodiments (and/or aspects thereof) may be used in combination witheach other. In addition, many modifications may be made to adapt aparticular situation or material to the teachings of the inventivesubject matter without departing from its scope. While the dimensionsand types of materials described herein are intended to define theparameters of the inventive subject matter, they are by no meanslimiting and are exemplary embodiments. Many other embodiments will beapparent to one of ordinary skill in the art upon reviewing the abovedescription. As used herein, the terms “including” and “in which” areused as the plain-English equivalents of the respective terms“comprising” and “wherein.” Moreover, as used herein, the terms “first,”“second,” and “third,” etc. are used merely as labels, and are notintended to impose numerical requirements on their objects.

This written description uses examples to disclose several embodimentsof the inventive subject matter and also to enable a person of ordinaryskill in the art to practice the embodiments of the inventive subjectmatter, including making and using any devices or systems and performingany incorporated methods. The patentable scope of the inventive subjectmatter may include other examples that occur to those of ordinary skillin the art. Such other examples are intended to be within the scope ofthe clauses if they have structural elements that do not differ from theliteral language of the clauses, or if they include equivalentstructural elements with insubstantial differences from the literallanguages of the clauses.

The foregoing description of certain embodiments of the inventivesubject matter will be better understood when read in conjunction withthe appended drawings. To the extent that the figures illustratediagrams of the functional blocks of various embodiments, the functionalblocks are not necessarily indicative of the division between hardwarecircuitry. Thus, for example, one or more of the functional blocks (forexample, processors or memories) may be implemented in a single piece ofhardware (for example, a general purpose signal processor,microcontroller, random access memory, hard disk, and the like).Similarly, the programs may be stand-alone programs, may be incorporatedas subroutines in an operating system, may be functions in an installedsoftware package, and the like. The various embodiments are not limitedto the arrangements and instrumentality shown in the drawings.

As used herein, an element or step recited in the singular and proceededwith the word “a” or “an” should be understood as not excluding pluralof said elements or steps, unless such exclusion is explicitly stated.Furthermore, references to “an embodiment” or “one embodiment” of theinventive subject matter are not intended to be interpreted as excludingthe existence of additional embodiments that also incorporate therecited features. Moreover, unless explicitly stated to the contrary,embodiments “comprising,” “including,” or “having” an element or aplurality of elements having a particular property may includeadditional such elements not having that property.

What is claimed is:
 1. A method for detecting the presence of a vehicleon a railway track, using a sensing processor monitoring a sensingsystem for detecting vibration into ground installed along the railwaytrack and comprising a detection module for detecting a vehicle on therailway track, the method comprising an initialization step comprisingthe sub-steps of: at an initialization device, emitting a first signalto be received by the sensing processor through the sensing system; atthe initialization device, sending to the sensing processor, a firstmessage comprising configuration data chosen among, location of theinitialization device, intensity/magnitude of the first signal, emissiontime of the first signal, type of object corresponding to the firstsignal; at the sensing processor, monitoring the sensing system; and atthe sensing processor, configuring the detection module in function ofthe received first signal and the received configuration data.
 2. Themethod of claim 1, wherein the emitting and sending sub-steps areapproximately realized simultaneously.
 3. The method of claim 1, whereinthe configuration data comprise the first signal intensity and duringthe configuring sub-step a set of measured data relative to the receivedfirst signal are memorized and are associated with the configurationdata.
 4. The method of claim 3, wherein during the configuring sub-stepthe memorized set of measured data is associated with a type of detectedobject, according to the signal intensity comprised in the associatedconfiguration data and preferentially is associated also with a locationof the type of detected object determined in function of the location ofthe initialization device comprised in the configuration data.
 5. Themethod of claim 3, wherein the memorized set of measured data isrelative to a general form of the first signal monitored by the sensingprocessor through the sensing system and corresponds to a signalsignature associated with a type of detected object.
 6. The method ofclaim 3, wherein following the initialization step, the method comprisesa detecting step comprising the sub-steps of: at the sensing processor,monitoring the sensing system; and at the sensing processor, comparingone or more received second signal with each memorized set of measureddata in order to determine a type of detected object circulating on therailway track and preferentially also its location.
 7. The method ofclaim 4, wherein following the initialization step, the method comprisesa detecting step comprising the sub-steps of: at the sensing processor,monitoring the sensing system; and at the sensing processor, comparingone or more received second signal with the memorized set of measureddata in order to determine a type of detected object circulating on therailway track and preferentially also its location.
 8. The method ofclaim 1, wherein the initialization step is realized several times for agiven location of the initialization device, different first signalshaving different intensity levels being successively emitted, theinitialization device being moved along the track during theinitialization step.
 9. The method of claim 8, wherein following theinitialization step, the method comprises a detecting step comprisingthe sub-steps of: at the sensing processor, monitoring the sensingsystem; and at the sensing processor, comparing one or more receivedsecond signal with each memorized set of measured data in order todetermine the type of object circulating on the railway track andpreferentially also its location.
 10. The method of claim 1, whereinduring the emitting sub-step several first signals having the sameintensity levels are successively emitted, while the initializationdevice staying preferably at the same location and wherein during theconfiguring sub-step the sensing processor is configured in function ofthe received first signals and the received configuration data.
 11. Themethod of claim 1, wherein the initialization device is movable alongthe railway track.
 12. The method of claim 1, wherein the initializationstep is repeated: at predetermined time intervals, or each time anactivator on the initialization device is activated, or when theinitialization device is not moving for a predetermined amount of time.13. The method of claim 1, wherein the method comprises a security stepcomprising sub-steps of: at a calibration device, outputting a thirdsignal to be received by the sensing processor through the sensingsystem; at the sensing processor, monitoring the sensing system; and atthe sensing processor, determining if a signal level of the third signalis within a predetermined threshold.
 14. The method of claim 13,wherein: the sub-step of determining if the signal level of the thirdsignal is within the predetermined threshold includes verifying if atleast one of the calibration device or sensing system has moved.
 15. Themethod of claim 1, wherein the first signal is an acoustic signal andpreferentially a vibration signal sent into the ground.
 16. The methodof claim 3, wherein the method comprises a control step comprisingsub-steps of: at a control device, outputting a fourth signal to bereceived by the sensing processor through the sensing system; and at thesensing processor, modifying at least one of the memorized set ofmeasured data or data relative to a received second signal in functionof the received fourth signal.
 17. The method of claim 16, whereinfollowing the outputting of the fourth signal the control step comprisesthe following sub-step: at the control device, sending to the sensingprocessor, a second message comprising control data chosen among,location of the control device, intensity/magnitude of the fourthsignal, and emission time of the fourth signal.
 18. The method of claim16, wherein the fourth signal is outputted at predetermined times and/orduring predetermined time periods, the fourth signal havingadvantageously a predetermined intensity/magnitude and/or frequency. 19.The method of claim 16, wherein during the modifying sub-step thesensing processor compares the received fourth signal with pre-memorizeddata in order to detect changing in environmental conditions of therailway track, the at least one of the memorized set of measured data ordata relative to the received second signal being modified in functionof the detected changing in environmental conditions of the railwaytrack.
 20. The method of claim 1, wherein the sensing system comprises afiber optic cable.
 21. A detecting system for detecting the presence ofa vehicle on a railway track, comprising a sensing processor configuredto monitor a sensing system for detecting vibration into groundinstalled along the railway track, the sensing processor comprising adetection module for detecting a vehicle on the railway track whereinthe system comprises an initialization device configured to emit a firstsignal to be received by the sensing processor through the fiber opticcable and to send to the sensing processor a first message comprisingconfiguration data chosen among, location of the initialization device,intensity/magnitude of the first signal, emission time of the firstsignal, and wherein the sensing processor comprises a configurationdevice adapted for configuring the detection module in function of thereceived first signal and the received configuration data.